Ys6 shafts from 904f woods

It can be done, but the issue is getting a real Titleist SureFit Adapter. You cannot purchase adapters from Titleist. If you can find a used 913 or 915 fairway wood shaft, you can have a repair person pull the adapter off the shaft and transfer it to your YS6. With all that said, it's much easier to just order a new fairway wood with the YS6 installed. There is an uncharge, but it won't break the bank.

You will probably be better off if you get fitted for the proper shafts to go with your new clubs. The shafts are included and you can't buy the heads without shafts. It will just be an added expense.

There are a lot of great shafts available at no additional cost these days. Your fitter is definitely your friend.

A competent golf shop can do this, but will likely need to use an after market adapter. Titleist only supplies complete shafts. Unless you have a Titleist fairway shaft that the shop can pull the adapter.